BWT901CL | manual v0707 | http://wiki.wit-motion.com/english
Step 4. After rotation, click “End calibration”
Successful result:
Most of data dots will be within the ellipse.
If not successful, please stay away from the objective that can create magnetic
field interference.
2.3.3 Gyroscope Automatic Calibration
The gyroscope calibration is to calibrate the angular velocity, and the sensor
will calibrate automatically.
It is recommended that the automatic calibration of gyroscopes can be
inactivated only if the module rotates at a constant speed.